Porous materials can be useful in a variety of different applications. For example, porous materials can be used as sorptive media, as gas separation membranes, as the detection material in various sensors, as catalysts, and as light weight materials. In some applications, porous materials with micropores (i.e., pores less than 2 nanometers) are particularly useful. Many of the state-of-the art microporous materials are made using expensive raw materials, and/or are made using processes that are limited to the preparation of fairly small quantities, and/or are difficult to process into useable forms. Additionally, because of the instability of some of these materials under ambient conditions, the total porosity can deteriorate over time and usage.
Some example microporous materials of interest are polymers with intrinsic microporosity. One example synthesis method for this type of polymeric material is shown in Reaction Scheme A where 5,5′,6,6′-tetrahydroxy-3,3,3′,3′-tetramethyl-1,1′-spirobisindane is reacted with 2,3,5,6-tetrafluoroterephthalonitrile to form a polymeric material with fused dioxin rings as linking groups. These polymers and their synthesis methods are described more fully, for example, in Budd et al., Chem, Commun., 2004, 230 and in U.S. Pat. No. 7,690,514 (McKeown et al.).

Polymers with intrinsic microporosity are characterized by a rigid backbone containing regular points of contortion. This characteristic of the backbone results in poor packing of the polymeric chains with each other. The interstitial space between the polymer chains tends to result in microporosity. The surface area of these polymers can be greater than 600 m2/gram, greater than 700 m2/gram, or even greater than 800 m2/gram. Unlike many other microporous materials, these polymers are soluble in many common organic solvents and advantageously can be coated from a solution to form a microporous coating. On the other hand, the polymers with intrinsic microporosity typically are not suitable for applications that require large volumes of material. The polymerization times tend to be lengthy (e.g., several days) and the monomers used to form the polymers are often quite expensive.